The San Antonio Center for Research in Reproductive Biology is a multidisciplinary research effort, oriented to the development of new alternative methods of contraception. We are investigating reproductive mechanisms at several levels, including: neuroendocrine control of ovulation; hormone-receptor-chromatin interactions in breast, oviduct, and uterus; regulation of tubal transport; and control of male reproduction. Our definitive objective is utilization of the information acquired to design innovative methods of contraception. Eight senior scientists form the Research Program Committee of the Center. Each supervises the activities of less established investigators within his area of special competence. Nineteen scientists are involved in the Center. The applicant institution has demonstrated, by past and present actions, a strong commitment to research and training in population-related fields.